Screen MCP

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden of behavioral disclosure. It describes the tool's role in a multi-step flow and mentions temporary storage, which adds useful context. However, it lacks details on permissions, rate limits, error conditions, or what 'temporary' means (duration, cleanup). For a tool with 6 parameters and no annotations, this is a moderate gap.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is highly concise and well-structured: two sentences that front-load the purpose and follow with specific usage steps. Every sentence earns its place by providing essential guidance without redundancy or fluff.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's complexity (6 parameters, no annotations, but with an output schema), the description is partially complete. It explains the workflow and purpose well, but lacks parameter explanations and behavioral details. The output schema may cover return values, but for a tool initiating a capture process, more context on parameters and behavior would improve completeness.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description must compensate for undocumented parameters. The description mentions 'chunked session' which hints at 'chunk_size', but does not explain any of the 6 parameters (e.g., 'duration_seconds', 'monitor_index', 'image_format'). It fails to add meaningful semantics beyond what the bare schema provides, leaving parameters largely unexplained.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's purpose: 'Capture a timeline and store it in a temporary chunked session.' This specifies the verb ('capture'), resource ('timeline'), and storage mechanism ('temporary chunked session'). It distinguishes from siblings like 'capture_timeline' by emphasizing the chunked session aspect, though not explicitly contrasting with 'capture_screenshot' or 'start_screenshot_capture'.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides explicit usage guidelines: 'Use this as step 1 of the chunked timeline flow. Next calls should be: `get_timeline_manifest`, then all `get_timeline_chunk`, then `release_timeline_capture`.' This clearly states when to use it (step 1 of a specific flow) and what alternatives to use next, distinguishing it from other capture tools by outlining a sequential process.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.